| Message ID | 20210205020730.1746354-1-saravanak@google.com |
|---|---|
| State | Accepted |
| Commit | ced2af419528611bac9ffebb8e51aa59a8e9fca3 |
| Headers | show |
| Series | [v1] gpiolib: Don't probe gpio_device if it's not the primary device | expand |
Hi Saravana, On Fri, Feb 5, 2021 at 3:09 AM Saravana Kannan <saravanak@google.com> wrote: > Dmitry reported[1] boot error messages caused by > commit 4731210c09f5 ("gpiolib: Bind gpio_device to a driver to enable fw_devlink=on by default"). > > gpio-1022 (cpu-pwr-req-hog): hogged as input > max77620-pinctrl max77620-pinctrl: pin gpio4 already requested by max77620-pinctrl; cannot claim for gpiochip1 > max77620-pinctrl max77620-pinctrl: pin-4 (gpiochip1) status -22 > max77620-pinctrl max77620-pinctrl: could not request pin 4 (gpio4) from group gpio4 on device max77620-pinctrl > gpio_stub_drv gpiochip1: Error applying setting, reverse things back > gpio_stub_drv: probe of gpiochip1 failed with error -22 Similar issue on Salvator-XS: sh-pfc e6060000.pinctrl: pin GP_2_0 already requested by 7-0030; cannot claim for gpiochip9 sh-pfc e6060000.pinctrl: pin-64 (gpiochip9) status -22 sh-pfc e6060000.pinctrl: could not request pin 64 (GP_2_0) from group intc_ex_irq0 on device sh-pfc gpio_stub_drv gpiochip9: Error applying setting, reverse things back gpio_stub_drv: probe of gpiochip9 failed with error -22 > This happens because when we try to probe a device, driver core calls > into pinctrl to set up the pins. However, if the GPIO DT node already > has a proper device created and probed, trying to probe the gpio_device > with a stub driver makes the pins be claimed twice. pinctrl doesn't like > this and throws an error. > > So, this patch makes sure the gpio_stub_drv doesn't match with a > gpio_device if it's not the primary device for the fwnode. > > [1] - https://lore.kernel.org/lkml/544ad0e4-0954-274c-8e77-866aaa5661a8@gmail.com/ > Fixes: 4731210c09f5 ("gpiolib: Bind gpio_device to a driver to enable fw_devlink=on by default") > Signed-off-by: Saravana Kannan <saravanak@google.com> > Tested-by: Dmitry Osipenko <digetx@gmail.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Fri, Feb 5, 2021 at 3:07 AM Saravana Kannan <saravanak@google.com> wrote: > Dmitry reported[1] boot error messages caused by > commit 4731210c09f5 ("gpiolib: Bind gpio_device to a driver to enable fw_devlink=on by default"). > > gpio-1022 (cpu-pwr-req-hog): hogged as input > max77620-pinctrl max77620-pinctrl: pin gpio4 already requested by max77620-pinctrl; cannot claim for gpiochip1 > max77620-pinctrl max77620-pinctrl: pin-4 (gpiochip1) status -22 > max77620-pinctrl max77620-pinctrl: could not request pin 4 (gpio4) from group gpio4 on device max77620-pinctrl > gpio_stub_drv gpiochip1: Error applying setting, reverse things back > gpio_stub_drv: probe of gpiochip1 failed with error -22 > > This happens because when we try to probe a device, driver core calls > into pinctrl to set up the pins. However, if the GPIO DT node already > has a proper device created and probed, trying to probe the gpio_device > with a stub driver makes the pins be claimed twice. pinctrl doesn't like > this and throws an error. > > So, this patch makes sure the gpio_stub_drv doesn't match with a > gpio_device if it's not the primary device for the fwnode. > > [1] - https://lore.kernel.org/lkml/544ad0e4-0954-274c-8e77-866aaa5661a8@gmail.com/ > Fixes: 4731210c09f5 ("gpiolib: Bind gpio_device to a driver to enable fw_devlink=on by default") > Signed-off-by: Saravana Kannan <saravanak@google.com> > Tested-by: Dmitry Osipenko <digetx@gmail.com> > --- > Greg/Linus, > > This will need to go into driver-core because the Fixes is in > driver-core too. OK that seems to be the right solution. Maybe I would try to explain the situation in the comment in gpio_bus_match a bit more, but anyway: Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Yours, Linus Walleij
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 8e0564c50840..8ad679a928b0 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -56,8 +56,10 @@ static DEFINE_IDA(gpio_ida); static dev_t gpio_devt; #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */ +static int gpio_bus_match(struct device *dev, struct device_driver *drv); static struct bus_type gpio_bus_type = { .name = "gpio", + .match = gpio_bus_match, }; /* @@ -4199,6 +4201,18 @@ void gpiod_put_array(struct gpio_descs *descs) } EXPORT_SYMBOL_GPL(gpiod_put_array); + +static int gpio_bus_match(struct device *dev, struct device_driver *drv) +{ + /* + * Only match if the fwnode doesn't already have a proper struct device + * created for it. + */ + if (dev->fwnode && dev->fwnode->dev != dev) + return 0; + return 1; +} + static int gpio_stub_drv_probe(struct device *dev) { /*
Dmitry reported[1] boot error messages caused by commit 4731210c09f5 ("gpiolib: Bind gpio_device to a driver to enable fw_devlink=on by default"). gpio-1022 (cpu-pwr-req-hog): hogged as input max77620-pinctrl max77620-pinctrl: pin gpio4 already requested by max77620-pinctrl; cannot claim for gpiochip1 max77620-pinctrl max77620-pinctrl: pin-4 (gpiochip1) status -22 max77620-pinctrl max77620-pinctrl: could not request pin 4 (gpio4) from group gpio4 on device max77620-pinctrl gpio_stub_drv gpiochip1: Error applying setting, reverse things back gpio_stub_drv: probe of gpiochip1 failed with error -22 This happens because when we try to probe a device, driver core calls into pinctrl to set up the pins. However, if the GPIO DT node already has a proper device created and probed, trying to probe the gpio_device with a stub driver makes the pins be claimed twice. pinctrl doesn't like this and throws an error. So, this patch makes sure the gpio_stub_drv doesn't match with a gpio_device if it's not the primary device for the fwnode. [1] - https://lore.kernel.org/lkml/544ad0e4-0954-274c-8e77-866aaa5661a8@gmail.com/ Fixes: 4731210c09f5 ("gpiolib: Bind gpio_device to a driver to enable fw_devlink=on by default") Signed-off-by: Saravana Kannan <saravanak@google.com> Tested-by: Dmitry Osipenko <digetx@gmail.com> --- Greg/Linus, This will need to go into driver-core because the Fixes is in driver-core too. Thanks, Saravana drivers/gpio/gpiolib.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)